<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .active {
      text-decoration: underline;
    }
    .disabled {
      cursor: not-allowed;
    }
  </style>
</head>
<body>
  <div id="app">
    <div>当前是第{{currentPage}}页</div>
    <button
      v-bind:disabled="currentPage==1"
      v-on:click="change('-')"
      :class="{disabled: currentPage==1}"
    >上一页</button>
    <button 
      v-for="num in 5"
      v-on:click="change(num)"
      v-bind:class="{active:num == currentPage}"
    >{{num}}</button>
    <button
      :disabled="currentPage==5"
      v-on:click="change('+')"
      :class="{disabled: currentPage==5}"
    >下一页</button>
  </div>
  <script src="./vue.js"></script>
  <script>
    let vm = new Vue({
      el: '#app',
      data: {
        currentPage: 1
      },
      methods: {
        change(flag) {
          if(flag === '+' && this.currentPage<5) {
            this.currentPage ++;
          }else if(flag === '-' && this.currentPage>1) {
            this.currentPage --;
          }else if(flag>0) {
            this.currentPage = flag;
          }
        }
      },
    });
  </script>
</body>
</html>